Antioxidant and antiinflammatory activities of ventol, a phlorotannin-rich natural agent derived from Ecklonia cava, and its effect on proteoglycan degradation in cartilage explant culture.

Osteoarthritis is thought to be induced by the aging-related loss of homeostatic balance between degeneration and repair mechanism around cartilage tissue in which inflammatory mediators such as reactive oxygen species, cytokines and prostaglandins are prone to overproduction under undesirable physiological conditions. Phlorotannins are unique polyphenolic compounds bearing dibenzo-1,4-dioxin skeleton which are not found in terrestrial plants but found only in some brown algal species such as Ecklonia and Eisenia families. Phlorotannin-rich extracts of Ecklonia cava including ventol showed significant antioxidant activities such as DPPH radical scavenging, ferric ion reducing power, peroxynitrite scavenging and inhibition of LDL oxidation, indicating their possible antioxidative interference both in onset and downstream consequences of osteoarthritis.

Antioxidative properties of brown algae polyphenolics and their perspectives as chemopreventive agents against vascular risk factors.

Several polyphenolic compounds and complex mixtures were isolated from brown algae species. The 1,1-diphenyl-2-picryhydarzyl (DPPH) radical scavenging activity and ferric reducing antioxidant power (FRAP) of these compounds were evaluated to determine their physiological usefulness as antioxidants for vascular protection. The antioxidative protection of low-density lipoprotein (LDL) was also evaluated and compared with that of catechin, because the generation of oxidized LDL is one of the most active and specific risk factors contributing to atherogenesis.